- Patients with AML, except those with APL (acute promyelocytic leukemia), failing a single standard dose cytarabine based frontline induction regimen. The diagnosis of refractory AML is based on the presence of either > 10% blasts in marrow or blood or 5-10% blasts in either site together with cytopenia (Hb < 10 g/dL, or platelets < 100 x 109/L, or neutrophil count < 1.0 x 109/L).